I just bought my first dSLR a week ago (a D90) so I'm trying to figure out how to take the kind of pictures I like. It is certainly not easy, way too many variables to control! I really like landscape pictures. Consider this amazing picture published in the NY Times:

I know that the hardest part is probably composition, but lets assume you are there and see this picture in your mind. Then, how would you set your camera to take this picture (exposure/aperture/iso/...)? Which lens do you think it was used?

First of all you will have to wake up very early in the morning to get this kind of light and colors, no lens could help you with that.
This one was made using some ultra wide lens and very likely a gradual density filter.
After that it was finished in Photoshop.

Invest in higher quality primes and zooms and bracket your exposures. The sharper the lens, the more you have to work with in the details. You need to invest in Photoshop and learn how to use it to take full advantage of your investment. Photoshop is quite expensive, so less expensive programs like Adobe Lightroom 2, Photoshop Elements and others can get you started. Taking the picture is half the work. Post production, like the time in the darkroom for us old timers, is just as important to get those eye popping "wow" images.

Oh...and experience. Just start taking photos and learn from your successes and mistakes. Photos are ultimately made by the photographer, not the equipment.

as for this picture it looks like it was taken early morning, right before sun rise, classic 1/3 composition (read about rule of thirds, they almost always work great), with some additional guiding lines caused by the river - guiding lines are very eye catchy so try to use them as often as it's possible, what else - straight horizon (very important at least at the beginning, most of the times You can correct it in PP (post processing)) and some PS work - probably a little saturation, contrast and levels tweaking, and adding mask to darken the corners (especially on the right side), that's why You can sometimes use vignetting - as darker corners makes human eye to go towards the middle part of the picture (brighter) and at the same time they add some dimension to the image

any way, it's a nice picture, but I guess that in a period of not less than one Year You should be able to take at least as good picture as this one, just practice as much as You can (and one of the best practices is to watch someone else pictures and comment on what You like and don't like)

if i was attempting to take this photo approaching the scene with my D90 i would have set the iso to 200, aperture to 6, then used Aperture Priority mode to get an appropriate exposure time; with exposure compensation set to -0.3.

from what i can read from the photo - i reckon its been cropped a fair amount; either that or they didn't use a prime. also; by the look of it they've used the time-tested approach (works brilliantly in Lightroom) of choosing a couple colours (most likely blue and yellow hues), reduced their luminosity while increasing saturation. looks a little under-exposed on purpose too, and bumped up in some areas to get a nice balance (hence why some people presume its an HDR composition).

1) It does look a bit HDR. look at the light of the reflected sky. Its about the same as the actual sky. This means that the author has increased the brightness of the reflected light and other dark areas or/and reduced the brightness of the sky. This usually done with layer masks

2) as mentioned by adamz there is some vignetting to bring the attention into the center. This is also usually done with layer masks.

3) There has been some things done to the colours probably what fraew suggested.

4) maybe a slight bump in contrast as well as saturation.

5) All the above is best done with the RAW file so you need to take the picture in RAW mode.

Being able to PP with a Raw Processor like Lightroom and Photo processing software like Photoshop is part of photography these days. I use the free versions of the above software. Its called UFRAW and TheGIMP. Or you can get Paint Shop Pro and click on the "smart Photo Fix" and it should do most of what was mentioned above. LOL.

If you read the article in the original post above, the author is talking about fishing into the night. So it's a sunset. This is what's called the "golden hour". You get really good lighting and a shot like that is fairly easy to get under that kind of light. The sun is to the left causing the bright colors to the right. The sky has a mix of dark clouds so that gives you a vignette feel. Look at the reflection in the water. It matches the colors in the clouds. If the edges were darkened in photoshop it wouldn't match up like that.

This is a NY Times article and they don't allow any kind of photo manipulation so HDR (High Dynamic Range)
it is definitely not. Although a slight color and layer adjustment is possible, I don't think that's what we're seeing here. Maybe only a slight contrast adjustment. I think the NY Times does allow that.

This is just a very nice photo taken by an experienced photographer/journalist.

Seba... making amazing pictures is harder than it would seem. I've only got a handful of my own out of thousands that I would deem acceptable to be my computers wall paper (not that making my wall paper is the gold standard of photography).

If you are after landscapes, then obviously location and timing will matter as much as your photographic skills. That said, when you start to move to smaller scales, then a lot more comes under your control. If you need to start somewhere start with exposure. Learning how your camera adjusts the exposure of the picture is half the battle. Eventually, you will learn to use this to your advantage.

Once you get a handle on how shutterspeed, aperture, and ISO all work together to create exposure, I'd venture that lighting is the next most important thing to learn (Its just as important as exposure really, but you have to understand exposure before you can effectively play with lighting. Go check out strobist for that sutff... they are really good.